Control apparatus for internalcombustion engines



Patented Mar. 2, 1954 CONTROL APPARATUS FOR INTERNAL- COMBUSTION ENGINES Scott F. Hunt, Meriden, Conn., assignor, by mesne assignments, to Niles-Bemcnt-Pond Company, West Hartford, Conn.',

Jersey a corporation of New Application November 15, 1946,Serial No. 710,021

15 Claims. 1

This invention-relates to control apparatus for internal combustion engines, and particularly to apparatus for controlling the supply of fuel and anti-detonant fluid to such engines.

, It has been proposed to provide an antianism so that the flow of anti-detonant fluid will be proportional to the flow of fuel. The particu lar proportion is predetermined and maintained by the system whenever it is in operation. The fuel system is usually constructed to supply a very rich mixture whenever the anti-detonant fluid supply system is not in operation. Therefore, it is customary to provide means, commonly termed a derichment valve, to reduce the fuel-air ratio whenever the anti-detonant fluid supply system is in operation.

. It is therefore an object of the present invention to provide an improved and simplified fuel and anti-detonant fluid supply system for an internal combustion engine.

Another object is to provide, in such a system improved means for controlling the anti-detonant fluid flow in proportion to the fuel flow.

, A further object is to provide, in such a system, improved derichment valvemeans.

Other, objects-and advantages-'ofthe present invention will become apparent from a consideration of the appended specification, claims and drawing.

Referring to the drawing, there is shown at If a. portion of an air supply conduit for an internal combustion engine. Combustion air enters the conduit at an entrance [2, and flows past a Venturi restriction M, a throttle l 6, and a fuel nozzle IE, to a discharge outlet 20.

Air flowing through the venturi 14 sets up a pressure differential therein .which is a measure of the volumetric rate of flow-of; air to the engine; This pressure differential induces a flowof air through a secondary air passage which may be traced from an impact tube 22 through a conduit. 24, a restriction 26, past a valve .28, into a chamber 30, and through a conduit 32 to the throat of venturi M. The valve 28 is operated by a bellows 34. The bellows 34 is filled with a fluid having an appreciable coeflicient of thermal expansion so as to give it a temperature response characteristic. The bellows 34 then responds both to the temperature and pressure of the combustion air flowing to the engine. It operates the valve 28 so that the pressure differential appearing across restriction 26 is a measure of the mass rate of flow of air to the engine. This air density compensating mechanism is more completely described and claimed in the patent to Milton E. Chandler, No. 2,393,144, dated January 15, 1946.

The air pressure diiierential appearing across restriction 26 is communicated through conduits 36 and 38 to chambers 40 and 42 in a fuel flow regulating valve mechanism generally-indicated at 44.

The chambers 40 and 42 are separated by a flexible diaphragm 46. The valve mechanism 44 also includes a chamber '48 separated from chamber 40 by a flexible diaphragm 50 and a chamber 52 separated from chamber 42 by a flexible diaphragm 54; The diaphragms 50, 4S, and are connected at their centers to the stem ofa valve 56.

Fuel for the engine comes from a tank 58 and flowsthrough a conduit 60, a fuel transfer pump 62, usually driven by the engine, past valve 56 into chamber 52; and thence through conduit 66, a-mixture control valve 68, conduits 10 and 12,.a jetsystem 14, a conduit 16, a chamber"! in a pressure regulator generally indicated at 80, past a valve 82 V in the pressure regulator and through a conduit 84 to the discharge nozzle l8.

The pump 62 is provided with a-pressurerelief valve 86, which maintains a substantially constant pump discharge pressure.-

The mixture control 68 includes a disc valve 88 flxedon a shaft'90. When th disc valve-88 is in the position shown in the drawing, fuel then can flow to the jet system'only through the conduit 10. This is known as the lean position of the mixture control. The valve 88 is movable to a position wherein both the conduits 10 and 12 are open to the flow of fuel. This is shown as the rich position of the mixture control. The valve 88 is also movable to a position wherein the flow through-both conduits l0 and 12 is cut off. This isknown as the-cut-oflpositionu Fuel entering the jet'system 74 through the conduit 10 may pass through either a fixed restriction 92, a restriction 94 controlled by an enrichment valve 96, which is biased to closed position by a spring 98, or through a restriction 1B0 controlled by a valve I62, which is part of a derichment valve mechanism generally indicated at 104. Fuel entering the jet system I l through conduit lz passes) through a fixed restrict-lent Iilr. Fuel iloiving 'thrua the restrictions: 94 and. I35 also passes through another restriction I98.

The chamber 38 in the fuel regulation valvemechanism i l is connected through. a. conduit. III to the main fuel conduit it on the downstream side of the jet system 74.. In the fuel regulating valve mechanism is; cheap: pressure differential across restriction 21a; which-isa measure of the rate of how of air to the engine, actsdownwardly on the diaphragm it and hence on the valve the jet system is, which for a given fuel metering area in that jet system, is a measure of the rate of flow of -iuel to the engine, acts upwardly on. the valve 55-, sincetlre high. pressure component of the fuel pressure differential. sets upwardly on diaphragm .53, while the lowpressure component acts downwardly on diaphragm 53; The valve 55 is therefore controlled in accordance with the balance between the air and fuel pressure differentials, and regulates the fuel fiow to maintain a: balance between those two diiferentials.

When the mixture control isin the lean position, the restriction 92 is the main meterin restri'ctiorr, and determines the relationship between the fuel pressure differential and the rate of'flow'of fuel. When the mixture control is in its rich position, the restriction I05 is connected inparallel with restriction 92; A new relationship between the fuel pressure differential and the fueliiow is then established, such that a greater fuel flow is obtained for a given pressure differential. when the fuel pressure differential exceeds a value determined by the strength of the spring 98; therebyincreasing the fuel-air ratio when the fuel pressure differential is above that value. The enrichment valve is provided to give a richer mixture at high enginepower outputs. such a rich mixture tends to prevent detonation and to make the engine run cooler. The restriction I08 is provided to limit themaximum flow which can take place thru restriction H35 and the enrichment valve 95.

Under normal operatin conditions, the restriction we is open in parallel with restriction 92 andwith it-determinesthe fuel-air ratio. The restriction M39 is closed by the valve I02 under conditions to be described later in connection with the anti-detonantfluid supplysystem.

The pressure regulatortllincludes a diaphragm I'I2 separating the chamber I8 from a chamber H4. The chamber I14 is-vented' as illustrated at' H6. The central portionof diaphragm H2 is attached to the stem of valve 82-. Valve 32 is biased toward closed position by-a spring H8.

The pressureregulator '85 functions to main tain a substantially constant pressure in the chamber'lt. If the pressure in chamber '58 increases above'that' constant value, the diaphragm H2 rises, compressing spring IIS and opening valve 82' wider. This movement continues until the valve 82 is opened sufii'ciently to restore the pressure in chamber I8 to its desired value; This pressure will not beabsolut'elyconstant, but will varytherefrom slightly because of the regulation of spring H8.

The anti-detonant fluid, which may bewatena The fuel pressure: differentialacross:

The enrichment valve Q8 opens water-alcohol mixture, or other suitable fluid, comes from a tank 426, and flows through a conduit 22, a pump #24, a conduit I25, a solenoid valve 22%, a metering restriction I28, a check valve I38, and a conduit 32 to the chamber I6 in pressure regulator 85.

The pump 24. may either. be engine driven or driven by a special motor, electric or otherwise, provided for that purpose.

The discharge. pressure of pump I2% is controlled by a relief'valve I 34. The relief valve I34 is in turn controlled by a pilot valve mechanism generally indicated at I38.

The conduit litat the discharge side of pump 1-2-4 is connected through a conduit I38 to a chamber Iii] located under the valve I34. The valve I341 is connected by a stem to a balancing diaphragm I42. The valve I34 separates chamber I49 from a chamber, Hi4 connected through a conduit M6 to the pump inlet conduit 122. The diaphragm I 52 separates chamber M4; from a chamber I l-ll connected through a conduit I59 to a port I52 adjacent a pilot valve I54, which is a part of the pilot valve mechanism I315:

The pilot valve 154 is of the. spool val've type, and is provided with recesses I55"- and iEi'son opposite sides of a land which, in the position shown in the drawing, blocks the port I 52. The recess l55 registers with a port leading through conduits Its and 552' to the pump discharge con:- duit i251 The recess T58- regi'sters with a 'port leading through a conduit 165 to thepumpinlet conduit I2 2;

The pilot valve ltd is attached to adiaphragm Its, which separates a pair ofexpansibl'e-chambers I6! and Iii]. Chamber I6! isconnected through conduits H2 and I74 t'o the main fuel conduit 65 on the upstream side of the jet systerm it. Chamber 1T0 is connected through the conduit I62 to the pump discharge conduit- I25.

The solenoid valve I28 is biased to closed" position and is opened by'energization oi'asolenoid coil IFS. The coil I75 is connected in a series circuit with a battery Ill? and a single pole snap switch I ii. Theswitch I39 is manually operable toopen orclose the solenoid.- valve at will.

The derichmentvalve mechanism Hi4 includes a diaphragm 82 separating expansible chambers I84 and I85. Chamber I84 is connected through conduit IN to the main: fuel line 66 on the upstream sideof the jet system I l. Chamber IE5 is connected through conduit I88 to. conduit I2? in the anti-detonant fluidsupply line on the upstream side of the metering restriction I128.

The check valve 353 is provided in the anti.- detonantfluid supply line to prevent backward flow of fuel into the anti-'detonantfluid system in case the fluid supply should become exhausted;

The energizing circuit for coil I16 is normally de-energized so that'valve is normally'closed. The pump I24 is normally'continuously running when the engine. is running, Whether a supply of anti-detonantfiuid is required or not. When.- ever'the pump I24 is running, whether the valve I 26 is open orc1osed,.the pilotvalve I36 regulates relief valve I34 so that the discharge pressure at pump I24 is exactly the. same as the pressure on the upstream side of the jet system I4. The pump discharge pressure is communicated to chamber where it acts upwardly on the underside of valve I34. This upward forceis opposed by" the downward force of spring I 49' and the downward force of thepressure in chamber I48. The diaphragm. I42 is so designed that its effective area is equalitothat of valve I34; Whenzitisso.de;-

:signed, the pressure in chamber I44 acts upwardthe pilot valve mechanism I36. This pilot valve.

mechanism I 36 includes the valve I54 which is positioned by diaphragm I 66 subject on its upper side to a pressure equal to that in the fuel line on the upstream side of the jet system and on its lower side to the discharge pressure at pump I24. As long as these two pressures are balanced, the diaphragm I66 and pilot valve I54 remain in the position shown in the drawing. If the pump discharge pressure becomes greater than the fuel pressure on the upstream side of the jet system, then the valve I54 is moved upwardly. This opens a fluid connection from the chamber I48 through conduit I50, port I52, recess I58 and conduit I64 to the pump inlet conduit I22. The pump discharge pressure acting upwardly-on valve- I 34 then forces diaphragm I42 upwardly, and forces fluid from chamber I48 out through the connec'-. tion just traced to the pump inlet. This upward movement of valve I34 reduces the pump dis-- charge pressure. As soon as the valve I34 has moved upwardly enough to reduce the pump discharge pressure to a value equalling the fuel pressure on the upstream side of the jet system, then diaphragm I66 is again balanced and valve I54 is restored to its neutral positionas shown in the drawing. This closes the pressure relieving connection from chamber I48 and thereby fixes the position of valve I34 at the position which produces balance between the pump discharge pressure and the fuel pressure on the upstream side of the jet system. v In a similar manner, if the pumpdischarge pressure falls below the fuel pressure on the up- 'stream-side of the jet' system, pilot valve I54 moves dov'lnwardly, opening a connection for supplying fluid at the pump discharge pressure through conduits I62 and I60, recess. I56, port I52 and conduit I 50 to the chamber I48. The chamber I48 then expands, moving valve I34 downwardly until the pump discharge pressure is thereby increased sufficiently to againbalance diaphragm I66. 1? It may therefore be seen that-the pilot valve I36 controls relief valve. I34 to'regulate the pump discharge pressure ata value equal to the fuel pressure on the upstream side of the jet sys-'- tem. It should be further noted that these two "pressures are maintained exactly equal by the system, and that the regulation of spring-l49 does not enter into the balance between the two pressures. If spring I68 is used to act onvalve I54, the two pressures will not be exactlyequal, but the pump discharge pressure-will be slightly higher, as required to balance the spring I68.

However, the proportionality between the two pressures will not be affected by spring 168, since under steady state conditions, its deflection is always the same. I

When the solenoid valve I26 is open by operation of the switch I80, then the anti-detonant fluid flows through metering restriction I28 and check valve I30 to chamber I8. Since the discharge pressure of pump I24, which is substantially the same as the pressure on the upstream side of metering restriction I 28, is maintained exactly equal to the pressure on the upstreamside of the jet system I4, it may be seen that a definite ratio is maintained between the fuel flow and the anti.-. detonant fluid flow. The pressures on the downstream side of the jet system and ontheidownstream side of the metering orifice I28are the same. I

When the solenoid valve I26 is open, the pressure on the upstream side of metering restriction I 28. is communicated through conduit I88 to chamber I86 in the derichment valve mechanism I04. The pressure in chamber I84 of the derichment valve mechanism is always the same as the pressure on the upstream side of the jet system. Since these two pressures are maintained equal by the pump discharge pressure control mechanism, then as long as the solenoid valve I26 is open, the only force acting on diaphragm I82 is that of spring I81, which accordingly moves valve I02 to closed position. This decreases the fuel flow by an amount to compensate for the increased flow of anti-detonant fluid through metering restriction I28.

If the solenoidvalve is then closed, or ifthe supply of anti-detonant fluid fails for any reason, then the pressure in chamber I86 falls until it is substantially equal to that on the downstream side of jet system 14. At least, it can be'no higher than that pressure, since if it were higher, check valve I30 would open until the pressure was reduced to the required value.- The pressure in chamber I84, however, still remains equal to the pressure on the upstream side of the fuel jet system I4, and therefore the full fuel pressure differential acts on diaphragm I82 downwardly against spring I87 and opens the valve I02. Hence, if the water supply system should fail, the derichment'valve I02 will be operated-in a safe direction, to increase the enrichment of-the fuelair mixture. I V

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention in the use of such terms and expressions, of excluding any equivalent of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of'the appended claims.

I claim as my invention:

1. A fuel and anti-detonant fluid supply sys-.- tem for an internal combustion engine, comprising a conduit forfuel flowing to said engine, a fuel. metering restriction in said fuel conduit, means for maintaining a substantially constant pressureon one side of said restriction, means for regulating the fuel pressure on the opposite side of said restriction to control the fuel pressure difierential across said restriction and hence the rate of flow of fuel to said engine, a-conduit for anti-detonant fluid'flowin'g to said engine, a pump-"for forcing anti-detonant fluid thru said last-mentioned conduit, afluid metering restric tion-in said fluid conduit downstream from said pump, a relief valve for regulating the: pump discharge pressure, a pilot valve for controlling said relief valve, and means directly. subjected to said discharge pressure and to said regulated fuel pressure for controlling said pilot valve'to maintain Said pump discharge pressure propor-'- tional to said regulated fuel pressure and thereby to maintain said anti-detonant fluid flow proportional to said fuel flow.

2. A fuel and anti-detonant fluid supply system for an internal combustion engine, comprising a conduit for fuel flowing to said engine, a fuel metering restriction in said fuel conduit, means for maintaining a substantially onstant pressure on the downstream sideof sa-idrestricion, means for regulating the fuel pressure on the. upstream side: of said; restriction. to. control the fuelipressure difierentiai across said 1551313.-

tion and hence the rate of flow of fuel too said -engine,;.a conduit for antia-d'etonant fluidiflowing to? said: engine: and: delivering saida fluid. into 1 said fuel conduit at the. downstream: sideof; said restriction; a pump'for forcing anti-detonantw fluid thrue saidr' last-mentioned. conduit; a' fluidimetering restriction: in said: fluid conduit downstream from. said pump a: relief valve for regulating, the pump: discharge: pressure; av pilot valve; for controlling saidrelief valve; and means: directly: subject'ed to said discharge pressure and to said regulated fuel: pressure for. controlling said pilot valve: to maintainsa-id pump dis-charge: pressure proportional. to: saidi regulated fuel: pressure and thereby to-maintain said anti-detonant fluid flow proportional to saidifuel, flow;

3. A fuel and anti-detonant fluidsupply's ys vtem: for am internai combustion: engine, comprisdetona-nt fluidflowing to-said engine, a pumpfor forcing: anti-detonant fluid thru said last-men.- tioned conduit, a fluid metering restriction in saidfluidconduit downstream from said. pump, means: for maintaining asubstantially constant fluidpressureon the downstream sideof said restriction, and. pump by pass relief valve. means directly subjected to. said regulated fueL pressure: forrreguiating the. pump discharge pressure to: maintain. said. pump dis-chargev pressure propontionali to: said regulated fuel pressure. and thereby to maintain said anti-detonant fluid flow proportionalto said fuel-flow.-

4.. Av fuel and. antiedetonant fluid. supply. system-for an: internal combustion engine,,comprising a conduitfor fuel flowing tosaid engine having a, metering; restrictiontherein, a. conduit. for antis-detonant fluidflowing to] said engine, a pump for forcing antiedetonant fluid thru. said last-mentioned conduit, a fluid meteringrestriction in said fluid conduit downstream fromsaid pump, means for. maintaining a. substantially constant fluid. pressure. on. the. downstream side of said restrictions, and pump. by-pass relief valve: means directly subjected to the unmetered fuel. pressure in said fuel conduit for maintaining the discharge pressure of said pump. pro.- nortional to said unnietered fuel pressure, where.- bysaid anti-detonant fluidv flow is, proportional to: said fuelflow;

5: A fuel: and anti-detonant fluid; supply.- system-for an internal; combustion engine,- comprising; a: conduit for combustion ain'flowing' to said engine; a. conduit for. anti detonant. fluid flowing to saidengine, a. pump for. forcing antiedetonant fluid thru said last-mentioned. conduit, a fluid metering restriction in saidfluid conduit downstream fromsaid pump, means for maintaining a substantially constant fluid pressure on the downstream side of said restriction, and. pump by pass relief valve means responsive to the rate of'massflow'ofcombustion air to said engine for controlling the discharge pressure of said pump so as to maintain said anti-detonaflt fluid flow constantly proportional to said air flow.

6. A fuel and anti-detonant fluid supply system'for'an internal combustion engine, comprisinga'conduit for fuel flowing to said'engine, fuel metering restriction means in said conduit, means for maintaining a substantially: constant pressure on the downstream side of said fuel S metering'restrictionmeans; means foirregulating the fuel; pressure. on; the upstream side of said restriction; mean to: control: the flow of fuel? to said engine a. conduit. for anti-detonant. fluid flowing to: said engine and. delivering intosaid fuel; conduit J at the: dowi'istreamside of said fuel metering restriction",.a fluid metering restriction in; said fluid conduit, means: for regulating; the pressure on. the upstream side of" said: fluid metering restriction a derichment valve effective upon: movement. from: open. to closedv position:- to decrease the area. of: said1fuel; metering restriction means;,means biasingssaidzderichment valve to closed position, a. diaphragm; attached: to; said valve, means: for subjecting; one: side. of. said. diaaphragm; to. said regulated fuel pressure sothat said regulated fuel pressureacts on; said. diaphragm in adirection to: open said valve, and. means for subjecting the. opposite side: of said diaphragm to-said regulated fluid pressure.

7. A. fuel. and antiedetonant fluid supply. system' for. an internal; combustion engine, compriseing; azconduit for fuel: flowing to said engine fuel metering restriction; means, in: said conduit. means for maintaining a; substantially constant pressureonthe: downstream sideof. said fuel metering restriction means, means for regulating the fuel pressure onthe upstream side of said restriction means to; control the flow: of: fuel. to said engine, aconduit. for antiedetonant fluid flowing to.:said engine and delivering into said fuel conduit atthe downstream side of said fuel metering restriction, a. pump for forcing, antidetonantfluid thru saidylast.mentionedconduit, a1. fluid. metering restriction in said.- fluid. conduit downstream. from. said: pump; a. relief valve. for regulating the pump discharge: pressure, apilot valve for controlling saidirelief valve, andmeans directly subjected torsaid dischargepressureand to said regulated fueL pressure for. controlling saidpilotvalve to maintain saidpump. discharge pressure proportional to'saidregulated fuel pres.- sureand thereby to: maintain said antirdet'onant fluid: flow'proportionalto said fuelzfiow, a. derichment valve. effective upon movement. from open to closed position to decrease. the area of said fueL metering restriction. means, means biasing said derichment valve to closed position 2,. diaphragmzattachedto said valve, meansfor, subjecting onezsideof. said diaphragm torsaid. regulated. fuelpressure so that. said. regulated. fuel pressure actson. said. diaphragm. ina direction to; open said. valve, and means for subjecting the opposite sideof said diaphragmto saidregui'ated fluid pressure,

8. A- fuelsandv anti.- detonantfluidsupply. system for. an internal combustion engine, comprising, a. conduit for. fuelflowing to saidengine, fuel meter.- ing; restriction means insa-id. conduit,. means for regulating. the fuel pressure in. a portion of said conduit in. accordance with therateof flow of fuelto said engine, a conduit for anti-detonant fluidflowing tdsaid engine, a fluid metering. restriction in said fluid conduit, means for main? taining. asubstantially constant fluid pressure on the downstream. side of. said fluid. metering. restriction, means for regulating. the pressure. on theupstream sideof said fluid metering restriction, a derichrnent valve effective-upon movement from opento. closed-position to. decrease thewarea of said fuel metering restriction means, means biasing said derichment valve toolosed position, a diaphragm attached. to. said, valve, means. for subjecting one side of said diaphragm to said regul'atedafueLpressure so that said regulated.- fuel conduit for fuel flowing to said engine, fuel meter ing restriction means in said conduit, means for regulating the fuel pressure in a portion of said conduit in accordance with the rate of flow of fuel to said engine, a conduit for anti-detonant fluid flowing tosaid engine, a fluid metering restriction in said fluid conduit, means for maintaining a substantially constant fluid'pressure on the downstream side of said fluid metering restriction, means for regulating the pressure on the upstream side of said fluid metering restric; tion, a derichment valve effective upon movement from open to closed position to decrease the area of said fuel'meterin'g restriction means, means biasing said'derichment valve torclosed position, and operating means for said valve'subject to said regulated fuel pressure acting in a valve opening direction and to said regulated fluid pressure acting in a valve closing direction.

10. A fuel and anti-detonant fluid supply system for an internal combustion engine, comprising a conduit for fuel flowing to said engine, fuel metering restriction means in said conduit, means for regulating the fuel pressure in a portion of said conduit in accordance with the rate of flow of fuel to said engine, a conduit for anti-detonant fluid flowing to said engine, a fluid metering restriction in said fluid conduit, means for maintaining a substantially constant fluid pressure on the downstream side of said fluid metering restriction, means for regulating the pressure on the upstream side of said fluid metering restriction, a derichment valve effective upon movement from open to closed position to decrease the area of said fuel metering restriction means, and operating means for said valve subject to said regulated fuel pressure acting in a valve opening direction and to said regulated fluid pressure acting in a valve closing direction.

11. A fuel and anti-detonant fluid supply system for an internal combustion engine, comprising a conduit for fuel flowing to said engine, fuel metering restriction means in said conduit, means for maintaining a substantially constant pressure on the downstream side of said fuel metering restriction means, means for regulating the fuel pressure on the upstream side of said restriction means to control the flow of fuel to said engine, a conduit for anti-detonant fluid flowing to said engine and delivering into said fuel conduit at the downstream side of said fuel metering restriction, a pump for forcing anti-detonant fluid thru said last-mentioned conduit, a fluid metering restriction in said fluid conduit downstream from said pump, means for regulating the pump discharge fuel pressure in response to said discharge pressure and to said regulated fuel pressure to maintain said pump discharge pressure proportional to said regulated pressure and thereby to maintain said anti-detonant fluid flow proportional to said fuel flow, a derichment valve effective upon movement from open to closed position to decrease the area of said fuel metering restriction means, means biasing said derichment valve to closed position, and operating means for said valve responsive to the difference between said regulated fuel pressure and said regulated fluid pressure, said regulated fuel pressure acting in a valve opening direction and said regu.

, 10 I latedfluid pressure actingin a valve closing 'di-1 rection.

.12. A fuel and anti-detonant fluid supply system for an internal combustion engine, comprising a conduit for fuel flowing to said engine, fuel metering restriction means in said conduit, means for regulating the fuel pressure in a portion of said conduit in accordance with the rate of flow of fuel to said engine, a conduit for antidetonant fluid flowing to said engine, a pump for forcing anti-detonant fluid thru said last-mentioned conduit, a fluid metering restriction in said fluid conduit downstream from said pump,-

means for maintaining a substantially constant 1 pressure on the downstream side of said fluid metering restriction, means for regulating the pump discharge pressure in response to said discharge pressure and to said regulated fuel pressure to maintain said pump discharge pressure proportional toisaid regulated fuel pressure and thereby to maintain said anti-:detonant fluid". flow proportional to said fuel flow, a derichment valve effective upon movement from open to closed position to decrease the area of said fuel metering restriction means, means biasing said derichment valve to closed position, and operating means for said valve responsive to the difference between said regulated fuel pressure and said regulated fluid pressure, said regulated fuel pressure acting in a valve opening direction and said regulated fluid pressure acting in a valve closing direction.

13. A fuel and anti-detonant fluid supply system for an internal combustion engine, comprising a conduit for fuel flowing to said engine, fuel metering restriction means in said conduit, means for regulating the fuel pressure in a portion of said conduit in accordance with the rate of flow of fuel to said engine, a conduit for anti-detonant fluid flowing to said engine, a fluid metering restriction in said fluid conduit, means for maintaining a substantially constant fluid pressure on the downstream side of said fluid metering restriction, means for controlling the pressure on the upstream side of said fluid metering restriction, an anti-detonant fluid cut-off valve between said pressure controlling means and said restriction, a derichment valve effective upon movement from open to closed position to decrease the area of said fuel metering restriction means, means biasing said derichment valve to closed position, and operating means for said valve subject to said regulated fuel pressure acting in a valve opening direction and to the anti-detonant fluid pressure between said cut-off valve and said fluid metering restriction acting in a valve closing direction.

14. A fuel and anti-detonant fluid supply system for an internal combustion engine, comprising a conduit for fuel flowing to said engine, fuel metering restriction means in said conduit, means for regulating the fuel pressure in a portion of said conduit in accordance with the rate of flow of fuel to said engine, a conduit for antidetonant fluid flowing to said engine, a pump for forcing anti-detonant fluid thru said last-mentioned conduit, a fluid metering restriction in said fluid conduit downstream from said pump, means for maintaining a substantially constant pressure on the downstream side of said fluid metering restriction, means for regulating the pump discharge pressure in response to said discharge pressure and to said regulated fuel pressure to maintain said pump discharge pressure proportional to said regulated pressure and thereby to mevomo maintain said anti-deterrent fluid flow :propor tional to said fuel flow, a cut-ofi valve between said pump and said restriction, a derichme'nt valve effective upon movement from open to closed position to decrease the area of said fuel metering restriction means, means biasing said derichment valve to closedpositionand operating means for said valve responsive to the difference between said regulated fuel pressure and the fluid pressure between said cut-01f valve and said restriction, said regulated ruelpressure acting in a valve opening direction and said fiuidpre'ssure acting in a valveclosing direction.

15. A system for mixing twofluids in predeter mined'proportions, comprising'a first conduit for a first fluid, metering restriction 'means in said conduit, means for regulating the flow =of said first fluid in said conduit, a second conduit-for a second fluid delivering into said fuel conduit at the downstream side of said meteringrestric 20 tion means, apu'mp Tor-forcing said second fluid thru said second conduit, a fluid metering restriction in said second :fiuid conduit downstream from said pump, a reiief valve fortregulating :the pump discharge pressure, a pilot valve for controlling said relief valve, and means directly subjected to said dischargeipressure and tofsaid regulated fuel pressure forcontrolling said pilot valve to 'maintain said vpump discharge pressure proportidnal to said regulated fuel pressure and thereby to maintain saidsecondfluid. flow proportional to said first flu-id fiow.

SCOTT F. HUNT.

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